Breakaway hose coupling with a magnetic connection

ABSTRACT

A breakaway coupling for a fuel supply hose includes a male valve body interfitting with a female valve body for defining a fuel passage, and the valve bodies enclose axially movable spring biased poppet valve members. The valve bodies are connected by a permanent magnetic coupling system which provides for moving the valve bodies from a connected position to a disconnected position in response to a substantial axial tension force on the valve bodies. In one embodiment, the coupling system includes an annular strike member surrounding the fuel passage and a mating annular magnet member supporting a plurality of circumferentially spaced permanent magnets of rare earth materials. In another embodiment, the valve bodies define a vapor return passage with a poppet valve member and disposed either radially outboard or inboard of the fuel passage. The magnetic coupling system also simplifies reconnecting the valve bodies.

RELATED APPLICATION

This application is a continuation of application Ser. No. 11/445,417,filed Jun. 1, 2006, now U.S. Pat. No. 7,252,112.

BACKGROUND OF THE INVENTION

The present invention relates to a breakaway coupling for a flexiblefuel supply hose and of the general type disclosed in U.S. Pat. No.4,691,941 and in U.S. Pat. Nos. 4,763,683, 5,433,247 and 6,899,131 whichissued to the assignee of the present invention and the disclosures ofwhich are herein incorporated by reference. The breakaway coupling maybe constructed for a coaxial hose as disclosed in the patents with afuel supply passage and a vapor return passage both of which haveaxially moveable valve members for closing the passages in the event thecoupling is separated. The present invention also relates to a breakawaycoupling having a single fuel supply passage with axially moveable valvemembers for closing the fuel supply passage in the male and femalecoupling bodies in the event of separation of the coupling.

In a breakaway hose coupling having a single fuel supply passage orcoaxial fuel supply and vapor return passages, the breakaway couplingprotects the fuel dispensing equipment from forces which may damage theequipment when separation of the coupling occurs. For example, when avehicle driver inadvertently forgets to remove the fuel dispensingnozzle from the fuel tank inlet tube and drives away, as discussed inabove-mentioned U.S. Pat. No. 4,691,941, the coupling separates when thehose receives a substantial axial tension force, for example, between200 and 400 pounds. Upon separation, the internal valve members move totheir closed positions to prevent the release of fuel from the couplingcomponents and attached hoses.

The female and male coupler bodies are releasably retained together byvarious means, for example, by a spring biased annular cam pressingagainst circumferentially spaced balls, as disclosed in above-mentionedU.S. Pat. No. 4,691,941, or by one or more shear pins, as disclosed inabove-mentioned U.S. Pat. No. 4,763,683 or by the use of an annular coilspring, such as disclosed in above-mentioned U.S. Pat. Nos. 5,433,247and 6,899,131. While the use of shear pins is the least expensive meansfor releasably connecting the coupler bodies, trained repair personneland significant time is required to replace the shear pins after thecoupler bodies have been separated. Since the use of thecircumferentially spaced balls and a spring biased cam ring results inan expensive connection of the coupler bodies, the use of an annularcoil spring has been adopted to reduce the cost of the releasableconnection of the coupler bodies and to permit reconnecting the couplerbodies. However, the use of annular coil springs results in variation inthe tension force required to separate or pull the coupler bodies apart.In addition, the annular coil spring connection also requires asignificant axial compression force to rejoin or reconnect the couplerbodies. It has also been determined that the hydraulic line shock orhammer effect produced in the fuel supply lines or hoses during shut offof the fuel supply by the dispensing nozzles results in wear of theshear pins and coil springs. This wear reduces the tension forcerequired to separate the coupler bodies and thus requires periodicmaintenance or replacement of the pins or springs.

SUMMARY OF THE INVENTION

The present invention is directed to an improved breakaway coupling fora flexible fuel supply hose and of the general type described above. Thebreakaway coupling of the invention provides for separating the couplerbodies with a substantially uniform and constant tension force which maybe selected and which greatly simplifies the reconnection or recouplingof the coupler bodies. A coupling constructed in accordance with theinvention may also be used with a flexible fuel supply hose with asingle fuel passage or with a coaxial fuel supply hose with a vaporreturn passage which may surround the fuel passage or be located withinthe fuel passage in order to accommodate a vapor assist fuel dispensingnozzle or a balance-type fuel dispensing nozzle.

In accordance with illustrated embodiments of the invention, a tubularmale coupler body and a tubular female coupler body of a breakawaycoupling are each provided with internal spring bias poppet valvemembers for closing the fuel supply passage and any vapor return passageupon separation of the coupler bodies. The coupler bodies are releasablyconnected in a coupled position by a coupling system including apermanent magnet system which mounts on one coupler body around the fuelsupply passage and mates with a strike member which mounts on the othercoupler body around the fuel supply passage.

In the illustrated embodiment, the magnet system includescircumferentially spaced magnets formed of rare earth materials, and themagnets are slightly spaced from the annular strike member when thecoupler members are connected. Both the magnet system and the strikemember are protected after separation of the coupler bodies byinterfitting annular protective or cylindrical semi-rigid covers orsleeves. The magnetic coupling system of the invention also provides forconveniently reconnecting or recoupling the coupler bodies.

Other features and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axial section of a breakaway coupling constructed inaccordance with the invention and having a fuel supply passage;

FIG. 2 is a radial section of the coupling, taken generally on the line2-2 of FIG. 1;

FIG. 3 is an end view of the coupling, taken generally on the line 3-3of FIG. 1, the opposite end view being substantially the same;

FIG. 4 is an axial section of another embodiment of a co-axial breakawaycoupling constructed in accordance with the invention and having both afuel supply passage and a vapor return passage;

FIG. 5 is a radial section of the coupling, taken generally on the line5-5 of FIG. 4; and

FIG. 6 is an end view of the coupling, taken generally on the line 6-6of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a breakaway hose coupling 10 which includes a tubularmale coupler body or body member 12 and a tubular female coupler body orbody member 14 which are formed of a metal such as aluminum and havecorresponding hexagonal outer end surfaces 16 and 18, respectively. Asshown in FIG. 1, the body members 12 and 14 are in their coupled orconnected position and are partially surrounded by interfitting annularor cylindrical sleeves or covers 20 and 22 molded of a semi-rigidplastics material such as nylon. The male cover 20 has an end portion 23which mounts on the body member 12 against an annular shoulder, and thecover 22 has an end portion 24 which mounts on a cylindrical surface ofthe body member 14. The inner cover 20 has an external groove whichcarries a resilient sealing or O-ring 27 which forms a fluid-tight sealbetween the covers 20 and 22. The body member 14 has an external groovewhich receives a resilient sealing or O-ring 29 which forms afluid-tight seal between the body member 14 and the outer cover 22 whichis secured by a spring retaining ring.

The body members 16 and 18 define an internal fuel supply passage 35 andhave outer end portions within internal threads 37 for receivingthreaded fittings, for example, on the end of a short fuel supply hose(not shown) extending from a fuel pump or dispenser and on a fuel supplyhose (not shown) extending to a fuel dispensing nozzle. A valve member42 is supported for axial movement within the center of the fuel supplypassage 35 by a guide stem 43 slidably supported within a center hole 44(FIG. 3) formed within a cylindrical disk or washer 46 havingcircumferentially spaced openings or holes 47 (FIG. 3). The disk orwasher 46 is retained within the body 16 and passage 35 by a springretaining ring 49. The valve member 42 is constructed as disclosed inabove-mentioned U.S. Pat. No. 6,899,131 and has tapered surfacesextending from an annular groove which receives a resilient sealing orO-ring 52 for engaging a tapered valve seat 54 formed within the valvebody 12. The valve member 42 also has a tubular inner end portion 56with a tapered inner end surface 57. A compression coil spring 59extends within an annular groove within the valve member 42 and engagesthe supporting disk or washer 46 for normally urging the valve member 42to a closed position where the sealing ring 52 engages the tapered valveseat 54.

The body member 14 also supports an internal valve member 62 constructedand supported as disclosed also in above-mentioned U.S. Pat. No.6,899,131. That is, the valve member 62 is supported for axial movementwithin the center of the fuel passage 35 by a guide stem 63 slidablysupported within the center hole 44 of another circular disk or washer46 having circumferentially spaced holes 47 and secured by anotherretaining ring 49. The valve member 62 also carries a resilient sealingring 52 and has an inner center pin portion 64 with a tapered endsurface mating with the tapered seat 57. Another compression coil spring59 extends within an annular groove within the valve member 62 andengages the disk or washer 46 for normally urging the valve member 62 toa closed position where the sealing ring 52 engages a tapered valve seat73 formed within the body member 14. Preferably, the valve members 42and 62 are molded of a rigid plastics material such as an acetal and arenormally retained in their retracted open positions (FIG. 1) when thebody members 12 and 14 are connected together. The operation of thevalve members 42 and 62 from open positions (FIG. 1) to closed positionsin response to separation of the body members 12 and 14, is the same asdisclosed in above-mentioned U.S. Pat. No. 6,899,131.

In accordance with the present invention, the body members 12 and 14 arereleasably connected together by a magnetic coupling system 80 which isillustrated in one form by an annular permanent magnetic member 82 andan annular strike member 84 both of which are formed of a plated ferrousmaterial or steel. The members 82 and 84 are secured to theircorresponding body members 12 and 14 by internal threads 86 and 87, andthe annular strike member 84 has a pair of diametrically opposed andaxially extending small holes (now shown) for threadably connecting thestrike member 84 to the body member 12 after the end portion 23 of thetubular protective cover 20 is mounted on the body member 12.

As shown in FIG. 2, the annular magnetic member 82 has a plurality ofcircumferentially spaced arcuate permanent magnets 95 which are recessedwithin an annular groove 96 formed within the member 82. The arcuatepermanent magnets 95 are retained within the groove 96 by anencapsulating film of adhesive or potting and bonding material, forexample, as sold under the trademark LOCTITE. Preferably, the magnets 95are formed of a rare earth material such as neodymium iron boron, andthe magnets 95 are arranged with common poles on the inside diameter andcommon poles on the outside diameter, with small gaps between themagnets. As shown in FIG. 1, the annular groove 96 which receives themagnets 95 does not extend completely through the annular member 82, andthe outer edge faces of the arcuate magnets 95 are slightly recessedfrom the end surface or face of the annular member 82. The recess ispreferably on the order of 0.005″ to 0.007″.

The magnetic attraction between the permanent magnet member 82 and thestrike member 84 provides for an attraction of substantial forcerequiring a tension force greater than 100 pounds to separate or pullthe body members 12 and 14 apart. Preferably, the attraction forcerequires over 200 pounds and on the order of about 240 pounds of tensionforce to separate the body members 12 and 14. After the body members 12and 14 have been separated as a result of the axial tension force, it isapparent that the magnetic coupling system 80 provides for convenientlyreconnecting the body members with only a small force to overcome theforces exerted by the springs 59 and the O-ring friction when the bodymember 12 is inserted into the body member 14. The magnetic attractionthen pulls the body members together. The force required to separate thebody members may be selected by increasing or decreasing the smallrecess space between the outer ends of the magnets 95 and the endsurface of the member 82 and/or increasing or decreasing the thicknessof the wall at the bottom of the groove which receives the magnets 95 orby perforating the bottom wall.

FIGS. 4-6 illustrate another embodiment or modification of the breakawaycoupling as described above in FIGS. 1-3 and which has similarcomponents as the breakaway coupling 10. Accordingly, the similarcomponents are identified with the same reference numbers but with theaddition of prime marks. The breakaway coupling 10′ is of the invertedtype, that is, has a center vapor return passage 105 surrounded by anannular fuel passage 110. The coupling 10′ includes a male body member12′ and female body member 14′. The body member 12′ supports aconcentric inner tube 114 having peripherally spaced positioning spokesor ribs 116 (FIG. 6) engaging a shoulder within the valve body 12′ andsecured by a retaining ring 117. The inner tube 114 supports an axiallyslidable tubular valve member 120 which carries a resilient sealingO-ring 123. A compression coil spring 126 urges the valve member 120towards a closed position where sealing ring 123 engages the annulartapered valve seat 54′. The inner tube 114 also supports an innertubular wire coil 129 having an axially extending straight end portionor pin 131 within the center of the tube 114.

The coupler body member 14′ also supports a center tube 142 which hasradially outwardly projecting spokes or ribs 143 engaging a shoulderwithin the body member 14′ and retained by another spring-type retainingring 117. The center tube 142 also supports an axially slidable valvemember 120 which carries a resilient O-ring seal 123 for engaging theannular tapered valve seat 73′ within the body member 14′. Anothercompression spring 126 urges the valve member 120 towards its closedposition, and the two valve members 120 have opposing end surfaces whichengage at 146 to hold the valve members 120 in their open positions whenthe body members 12′ and 14′ are coupled together, as shown in FIG. 4.The center tube 142 has a cylindrical inner end portion 152 whichprojects into the inner end portion of the center tube 114 and alsoforms an annular tapered inner valve seat 154.

A valve member 156 has a center hole which normally receives the innerend portion of the pin 131 and carries a resilient O-ring seal 157 forengaging the valve seat 154. A tapered compression wire spring 159 urgesthe valve member 156 towards its closed position. Thus when the couplerbody members 12′ and 14′ are separated, the valve members 120 move totheir closed positions to close the fuel supply passage 110 in both bodymembers, and the valve member 156 moves to its closed position forclosing the inner vapor return passage 105 within the coupler bodymember 14′. Thus the operation of the valve members within the couplerbodies 12′ and 14′ is substantially the same as disclosed in-connectionwith FIG. 9 of applicant's U.S. patent application No. 2005-0263193-A1,published Dec. 1, 2005 and assigned to the assignee of the presentinvention. The full disclosure of this published patent application isherein incorporated by reference, and the manual rotational separationof the breakaway hose coupling as disclosed in that application may alsobe incorporated in the hose coupling of the present invention.

The coupler bodies 12′ and 14′ are releasably connected together by thesame magnetic coupling system 80 as described above in connection withFIGS. 1-3. Accordingly, the same reference numbers are used in FIGS. 4-6to identify the same components of the magnetic coupling system 80 asdescribed above in connection with FIGS. 1-3. As apparent, the magneticcoupling system 80 may also be used for releasably connecting thetubular coupler bodies of a breakaway coupling of the balanced type, forexample, as disclosed in above-mentioned U.S. Pat. No. 4,763,683. Inthis type of coupling, the fuel vapor within a motor vehicle fuel tankis displaced by the incoming fuel and is directed back to the fueldispensing pump or dispenser through an annular outer vapor passagesurrounding the inner fuel supply passage both within the coupling andeach connected co-axial hose.

From the drawings and the above description, it is apparent that abreakaway hose coupling constructed in accordance with the invention,provides desirable features and advantages. For example, the magneticcoupling system 80 provides for releasably securing the tubular couplerbodies together with substantial force so that over 100 pounds andpreferably over 200 pounds of axial tension force is required toseparate the coupler bodies. This coupling force remains substantiallyconstant over time and is not subjected to wear. The magnetic couplingsystem also provides for conveniently and quickly reconnecting couplingbody members together with only a small axial force required to overcomethe forces exerted by the compression springs on the valve members andthe friction produced by the resilient O-rings between the couplingmembers and between the cover members. It is also apparent that when thecoupler bodies are separated, the surrounding cover 22 protects themagnet member 80, and the cover 20 protects the strike member 84 as wellas the tubular inner portion of the male coupler body. While the arcuaterare earth magnets 95 provide the desired substantial magneticattraction force while minimizing the overall diameter, it is apparentthat other forms of permanent magnets may be used, for example, as knownin the art of permanent magnets formed of rare earth materials.

While the forms of coupling herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of couplings, and that changes maybe made therein without departing from the scope and spirit of theinvention as defined in the appended claims.

1. A breakaway coupling adapted for use with a flexible fuel supply hosehaving a fuel supply passage, said coupling comprising a first bodymember and a second body member coupled together and defining a fuelsupply passage having an axis, a valve member within each of said bodymembers and movable axially within said passage between an open positionand a closed position for said passage, a coupling system releasablyconnecting said body members and providing for movement of said bodymembers from a coupled position to an uncoupled position in response toa substantial axial tension force on said valve bodies, said couplingsystem including an annular first magnetic coupling member mounted onsaid first body member concentrically with said axially movable valvemembers, an annular second magnetic coupling member mounted on saidsecond body member concentrically with said axially movable valvemembers, said first magnetic coupling member including circumferentiallyspaced separate permanent magnets each having an axial length greaterthan its radial thickness relative to said axis, said magnets arrangedaround one of said axially movable valve members and supported by anannular ferrous member having a radial thickness greater than saidradial thickness of each of said magnets, said magnets and said annularferrous member having generally co-planar radial end surfaces adjacentsaid second magnetic coupling member to complete a magnetic circuit whensaid body members are in said coupled position, and said first andsecond coupling members attracting each other in said coupled positionwith an axial force sufficient to require an axial tension force of atleast one hundred pounds to separate said body members to said uncoupledposition.
 2. A coupling as defined in claim 1 wherein said annular firstmagnetic coupling member has a radial thickness substantially equal to aradial thickness of said second magnetic coupling member.
 3. A couplingas defined in claim 1 wherein said annular second magnetic couplingmember has an axial length substantially equal to an axial length ofsaid first magnetic coupling member.
 4. A coupling as defined in claim 1wherein said first magnetic coupling member includes an annular outerportion and an annular inner portion integrally connected by an end wallportion cooperating with said inner and outer portions to define anannular groove, and said permanent magnets are disposed within saidgroove.
 5. A coupling as defined in claim 1 wherein said permanentmagnets comprise neodymium iron boron.
 6. A coupling as defined in claim1 wherein each of said permanent magnets has an axial lengthsubstantially equal to an axial length of said annular ferrous membersupporting said magnets.
 7. A coupling as defined in claim 1 whereineach of said permanent magnets is arcuate.
 8. A coupling as defined inclaim 1 wherein said second magnetic coupling member comprises anannular ferrous metal strike member secured to said second body member.9. A coupling as defined in claim 1 and including an annular first covermember having an end portion mounted on said first body member, anannular second cover member having an end portion mounted on said secondbody member, and one of said cover members surrounds the other of saidcover members to provide protection for said magnetic members in saidcoupled and uncoupled positions.
 10. A coupling as defined in claim 9and including a sealing ring between said cover members.
 11. A couplingas defined in claim 1 wherein said body members also surround a vaporreturn passage, and a spring biased valve member within said vaporreturn passage within one of said body members.
 12. A coupling asdefined in claim 1 wherein said first magnetic coupling member isthreadably connected to said first body member.
 13. A breakaway couplingadapted for use with a flexible fuel supply hose having a fuel supplypassage, said coupling comprising a first body member and a second bodymember coupled together and defining a fuel supply passage having anaxis, a valve member within each of said body members and movableaxially within said passage between an open position and a closedposition for said passage, a coupling system releasably connecting saidbody members and providing for movement of said body members from acoupled position to an uncoupled position in response to a substantialaxial tension force on said valve bodies, said coupling system includingan annular first coupling member mounted on said first body memberconcentrically with said axially movable valve members, an annularsecond coupling member mounted on said second body member concentricallywith said axially movable valve members, said first coupling memberincluding an annular permanent magnet member extending around one ofsaid axially movable valve members, said annular permanent magnet memberincluding an annular outer ferrous portion and an annular inner ferrousportion defining therebetween an annular groove receiving permanentmagnet means, and said first and second coupling members attracting eachother in said coupled position with an axial force sufficient to requirean axial tension force of at least one hundred pounds to separate saidbody members to said uncoupled position.
 14. A coupling as defined inclaim 13 wherein said annular inner ferrous portion is integrallyconnected to said annular outer ferrous portion by an end wall portionhaving an axial thickness less than said radial thickness of said outerferrous portion.
 15. A coupling as defined in claim 13 wherein saidsecond coupling member comprises an annular ferrous metal strike membersecured to said second body member.
 16. A coupling as defined in claim13 and including an annular first cover member having an end portionmounted on said first body member, an annular second cover member havingan end portion mounted on said second body member, and one of said covermembers surrounds the other of said cover members to provide protectionfor said coupling members in said coupled position and said uncoupledposition.
 17. A coupling as defined in claim 16 and including a sealingring between said cover members.
 18. A breakaway coupling adapted foruse with a flexible fuel supply hose having a fuel supply passage, saidcoupling comprising a first body member and a second body member coupledtogether and defining a fuel supply passage having an axis, a valvemember within each of said body members and movable axially within saidpassage between an open position and a closed position for said passage,a coupling system releasably connecting said body members and providingfor movement of said body members from a coupled position to anuncoupled position in response to a substantial axial tension force onsaid valve bodies, said coupling system including an annular firstcoupling member mounted on said first body member concentrically withsaid axially movable valve members, an annular second coupling membermounted on said second body member concentrically with said axiallymovable valve members, said first coupling member including an annularpermanent magnet member extending around one of said axially movablevalve members, said annular permanent magnet member including an annularferrous support member, said first and second coupling membersattracting each other in said coupled position with an axial forcesufficient to require an axial tension force of at least one hundredpounds to separate said body members to said uncoupled position, anannular first cover member having an end portion mounted on said firstbody member, an annular second cover member having an end portionmounted on said second body member, and one of said cover memberssurrounds the other of said cover members to provide protection for saidcoupling members in said coupled position and said uncoupled positions.19. A coupling as defined in claim 18 and including a sealing ringbetween said cover members.